1)3а²(2-в)
= 6а²-3а²в
2)(5а-6в)(6в-5а)
= -(6в-5а)(6в-5а)=-(6в-5а)²= -36в²+60ав-25а²
3)(х-у)(х+у)(х-у)=(х-у) (х²-у²)=х³-ху²-х²у+у³
2x-y=4 2(3+y)-y=4 6+2y-y=4 2y-y=4-6 y=(-2) y = -2
x-y=3 => x=3+y => x=3+y => x=3+y => x=3+(-2) => x = 1
<span>3х^2+1/4y^3
x = 1/3
</span>3х^2+1/4y^3 = 3*(1/3)^2+1/4y^3 = 3*1/9+1/4y^3 = (1/3)+(1/1)*3/4y^3 =
= (4/3)/4y^3
Здесь 2 признака треугольников